PTFE gaskets are flat gaskets, V-shaped gaskets, piston rings, ball valve gaskets, etc., made of Teflon rods, tubes and plates by mechanical turning or cutting. In fluid machinery (such as pumps, compressors, mixing kettles, centrifuges, etc.), the most severe operating conditions are considered to be teflon gaskets. It has good characteristics such as corrosion resistance, anti-aging and non-conductive. PTFE pH 0-14 (except for molten alkali metals and fluorine at high temperature and pressure). It can have good mechanical strength between -100℃ and 100℃ .
Characteristics of tetrafluoro gasket
Severity
In fluid machinery (such as pumps, compressors, mixing kettles, centrifuges, etc.), the most severe operating conditions are considered to be those of PTFE gaskets.
(1) Like thrust bearings, which receive axial forces.
(2) To export the generated heat like a heat sink.
(3) In the high temperature and high pressure corrosion-prone situation, the static seal is now very difficult, but also in the high-speed rotation, in a few millimeters of the sealing surface to complete the dynamic seal is even more difficult.
Operating environment
(1) No auxiliary system, you can only improve the seal layout, progress in raw materials. (High cost, can not solve the problem at the root)
(2) In practice, there are almost no teflon gaskets without any auxiliary equipment. Such as high pressure use of tandem tetrafluoro gaskets, high temperature tetrafluoro gaskets must choose the corresponding auxiliary equipment.
(3) (After the auxiliary system) the harsh conditions become acceptable conditions for sealing. (The role of PTFE gaskets is greatly improved, the application range is more extensive, the demand for sealing materials itself is reduced, and the cost of PTFE gaskets is reduced)
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Classification of PTFE gaskets
Teflon gaskets are mainly available in pure Teflon gaskets, Teflon sandwich gaskets, modified filled Teflon gaskets, etc. The mechanical strength of pure Teflon gaskets is very stable even in the range of minus 100 degrees Celsius to 100 degrees Celsius. However, when the temperature is too low, the pure teflon gasket will become brittle, so the working environment should not be lower than minus 185 degrees Celsius.
Teflon sandwich gasket not only has good corrosion resistance, but also has better compressive resilience than other gaskets, so it can be used in strong acid or alkali environment, and its pollution level is also very low.
The graphite-filled PTFE gasket with black PTFE gaskets is particularly good in sealing and compression, and has its own torque retention. The durability of the seal is further extended from the traditional seal. The use of graphite-filled teflon gaskets is environmentally friendly and cost saving to a certain extent because of the amount of filler added to the material used.
There is also an expanded teflon gasket made of PTFE resin sintered together, which has the special property that there are no problems regarding creep and cold flow, and the sealability and resistance is much better than other plate gaskets.
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